Press for printing, embossing, or printing and embossing.



Patented lune 25, l90l.

J. Y. JOHNSTON. PRESS FOB PRINTING, EMBOSSING, 0B PRINTING ANDEMBOSSING.

(Application filed Jan. 23; 1900. Renewed Apr. 23, 1901.) 1 (N0 Model.)5 Sheets-Sheet .l.

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No. 677,224. Patented June 25, I901; J. Y. JOHNSTON.

PRESS FDR PRINTING, EMBOSSING, 0R PRINTING AND EMBOSSING.

(Application filed Jan. 23, 1900. Renewed Apr. 23, 1901.) (No Model.) 5Sheets-Sheet 2.

m: Moms PETERS w. morouwa, wnsmnswu. B. c.

Patented June 25, I90I.

J. Y. JOHNSTON. PRESS FIIB PRINTING, EMBOSSING, 0B PRINTING ANDEMBOSSING.

' (Application. filed Jan. 23, 1900 Renewed Apr. 23, 1901.) (No Model.)5 Sheets8heet 3.

n: Mama's PETERS m. Pno'roumu. wuumsmu a No. 677,224. I Patented June25, l90l.

J. Y. JOHNSTON.

PRESS FOR PRINTING, EMBOSSING, 0R PRINTING AND EMBOSSING.

(Application filed Jan. 23, .1900. Renewed Apr. 23, 1901.)

(No Model.)

5 Sheets-Sheet 4.

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m w 5 2 e n u I. d e t n e t a P. N 0 T S N H nu L A" 2 2, 7 7 6 n PRESSFOB PBlNTlNG, EMBOSSING, 0R PRINTING AND EMBOSSING.

(Application filed Jan. 23, 1900. Renewed Apr. 23, 1901.)

5 Sheets-Sheet 5.

(No Model.)

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Utarrno STATES ATENT 'Ortrcn.

JOSEPH YARDLEY JOHNSTON, OF LONDON, ENGLAND, ASSIGNOR TO THE JOHNSTONNORTH AMERICAN PATENTS COMPANY, LIMITED, OF SAME PLACE.

ZCATIQN forming part of Letters Patent N0. 677,224, dated June 25, 1901.

Application filed January 23, 1900. Renewed April 23, 1901. Serial No57,117. (No model.)

To all whom may concern:

Be it known that I, JOSEPH YARDLEY JOHNS- TON, a citizen of the UnitedStates of America, residing at the city of London, England, haveinvented Improvements in Presses for-Printing, Embossing, or Printingand Embossing, of which the following is a specification.

My invention has reference to the impression mechanism of printing,embossing, or

ID printing and embossing presses in which the downward stroke of aplunger causes the engraved or other printing or embossing surface(hereinafter called a die) to strike the material to be printed orembossed, objects being to provide more effectually than heretoforeusual for preventing the die, after it has struck the material to beprinted or embossed and has once left the same, returning thereto untilthe proper time for its next stroke, for

2'0 enabling the plunger to rebound quickly and the die to leave thematerial immediately after the impression has been struck, and forobviating shock and vibration.

The accompanying drawings illustrate a convenient arrangement ofimpression mechanism according to this invention, which I will nowdescribe, promising that as here described my improved apparatus isapplied in a press which for convenienceof description I will assume isto be used for printing and which is so arranged that an arm adapted torevolve in a horizontal plane and carrying the die at its end firstpasses over apparatus which charges the die with ink, thenover a 5wiping apparatus which removes all superfluous ink, leaving only thefemale part of the die charged, and is then brought to rest and lockedin register over a counter, force,

male plate or other part between which and the die the impression is totake place, the

impression being then given by a blow of the die caused by the releaseand descent of the plunger from the raised position to which it had'beencarried and in which it had been locked during the preceding cycle ofoperations.

Figure 1 is a sectional elevation of the upper part of a press providedwith my improved mechanism for giving theimpression- 5o blow, theplunger being shown in its lowest position.

Figs. 2 and 3 show the said mechanism respectively in vertical and ahorizontal section, with certain portions in elevation, the plungerbeing shown in its highest position. Fig. 4 is a sectional plan showingcertain fixed parts only of said mechanism. Fig. 5 is a vertical sectionon the line A A, Fig. 4. Figs. 6 to 11, inclusive, are diagrammaticplans; and Figs. 12 and 13 are diagrammatic sections through Figs. 9 and10, illustrating the action of certain parts of the mechanism forraising, locking, and releasing the plunger. Figs. 14 to 17 are detailviews illus premature descent of the plunger.

Secured on the top of the'pressframe Ct is a cylinder or casing b, theaxis of which is in line with that of the shank of the block 0 carryingthe die cl when the latter is in registration. A plunger 6,screw-threaded at its lower partf, extends centrally through thecylindercasing b and works in a long nut g, secured within thepress-frame.

h is a spur-pinion formed on or secured to the plunger, and 2' is an armsecured above said pinion. j is a spur-wheel which is free to rotate onthe plunger above said arm. The plunger 6 is weighted by means of afly-wheel k, that is fixed by a nut Z upon a tapering polygonal part ofthe plunger. \Vhen it is desired to increase the force of the blowdelivered by the screw-plunger, one or more balance wheels or rings maybe secured to the fly-wheel.

m is a sleeve between the fly-wheel 7c and the spur-wheel j forpreventing end motion of the latter. Thus owing to the wheelj beingcompelled to move up and down Wit-h the plunger ethe weight of thefiy-Wheel maybe reduced, and shock caused by the plunger overrunning thewheel j while descending and meeting it during the rebound will beavoided.

The cylinder or casing is provided with a covern, formed'with a centralaperture which forms a bearing for a sleeve m and tends to preventvibration of the plunger and fiywheel and side strain and wear betweenthe screw and nut.

The pinion h gears with a pair of sliding racks 0, working in guides p,(shown in Figs. 1 and 2 only,) secured in the cylinder 1), par- 'tratingan arrangement for preventing the and the cam 11 has caught the roller7.

allel to each other. The racks 0 and the guides may be formed withreversely arranged ribs and grooves, the ribs being made a sliding fitin the grooves, as shown. The racks 0 terminate in heads g, which workin tubular boxes r, bolted to the cylinder 1), as shown. These boxescontain springs s and are closed by cap-nuts 2?, each of which is fittedwith a screw-spindle to, having an adjustable abutment or end piece 1:,a hand-wheel w, and lock-nut 4r. By screwing the spindles u in or outthe extent to which the springs s are compressed prior to the release ofthe plungencan be varied so as to regulate the force of theyimpression-blow as desired. hen the plunger partially rotates, so as torise from its lowest position, the racks 0 move outward freely duringthe first portion of their stroke.

Then their heads abut against the springs 3,.

them and the plunger to which they are geared 7 from pressure, so thatthe latter may deliver its blow freely and may be free to reboundquickly after the impression-blow is dGIiV'.

ered. Thelowerpartoftheplungerisformed with a number of screw-threads ofgreat or coarse pitch, so as to allowthe rebound to occur. i

The raising, locking, and releasing of the plunger are accomplished asfollows: On the main shaft 1 of the press is keyed a miterwheel 2, whichdrives another miter-wheel, 3, keyed on a shaft 4:, oirwhich is aspur-pinion 5, gearing with the spur-Wheelj, which is thus kept incontinuous rotation. The spurwheel j is intermittently connected 'to theplunger 6 by means of a connector compris ing a link 6, formed of acouple of connected plates and pivoted to the arm 6 of the plunger. Thelink is furnished with a drag-roller 7 and a lockingroller8, arranged atthe same level, and with a larger roller 9, occupying a higher position,the three rollers being arranged triangularwise, as seen in plan, Fig.3, with the roller 9 at the end of the link. Secured upon a ledge withinthe cylinder 1) is a guide 10, and fixed to the spur-wheelj is a cam-arm11, the forward edge of which comes incontact with the drag-roller '7,and so drags along with it the link 6, which is pivoted to the'arm 1',thus rotating and raising the plunger, the springs 8 being therebycompressed. This part of the action may be followed by reference toFigs. 6 and 7, which respectively show the posit-ion of the partsreferred to when the plunger is at the bottom of its stroke and when theplunger has rebounded The face of the said cam is so formed that itmakes contact with the roller 7 at the point at which a line passingthrough the axes of the roller 7 and of the pivot of the link 6 cuts thepe V riphery of said roller. connector is dragged around the tendency toforce the locking-roller 8 against the guide 10 is avoided until theroller 9 is brought. into contact with a fixed camplate 12. This plateis so shaped that as the roller 9 moves 7 V along it the free end of theconnector is deflected by it, (see Fig. 8,) so as tocause the roller 8to roll into a recess 13, formedin the end of the guide 10, the rearwardpart of the By this means as the" cam 11 as it continues its revolutionthen acting upon the roller 7 and forcing the roller 8 well home in thevrecess 13. (See Fig. 9.)

a if The formation of the recess '13 is such that V the roller 8 isretained therein after the cam,

11 has passed and the plunger c thus locked in the raised position, withthe springs s compressed ready to rotate the plunger re verse1y--i. 6.,in the direction required to 7 give the impression-blow-the action ofthe Springs tending to hold the roller 8 in the recess 13. The rollers-7, 8, and 9, in addition to performing the functions above men-Vtioned, also serve as antifriction-rollers. The 1 entry to the recess13that is to say, the

of the connector when the latter is in the part 10 of the guide 10iscurved, the curve 7 being struck from the center of the pivot-- lockedposition, Fig. at which time the center of the said pivot occupies thesame po-.

sition as at the time the cam llceases to drag i the link around. Thusthe roller is guided easily and without backlash intothe locked positionin the recess 13 by the outersurface of said cam 11,and yet is securelyheld in the f foo recess by the action of the springs s, since when inthat position a line passing through I05 theaxes of the pivot of thelink and ofthe roller 8 will lie outside the part 1O of the guide. (SeeFig. 9.) The release of the plunger is effected by a cam or trippingpiece 14,

fixedto the wheel j in such position'that at stored in them, the actualblow being given 7 by the further descent of the plunger owing to theinertia of the parts carried thereby and the continued action ofgravity. The upward or return movement of the plunger is therefore notresisted by the springs 3 until a considerable part of the rebound hasoccurred, thereby enabling the quick rebound so essential to goodresults to be obtained.

In the above-described impression mech- V anism, wherein the connectoris provided with rollers 7, 8, and 9 acting in conjunction with a guide10, having a specially-formed recess l3, and with a cam 11 and fixed cam12, friction is considerably reduced during the raising, locking, andreleasing of the screw-plunger, as also during the return motion afterrelease.

The lower end of the plunger 6 has secured to it a hardened-steel buttonor disk 15, and a cavity 16 is formed in the die-holder shank c toreceive a loose hardened-steel cylindrical piece 17, Fig. 1. The impactand friction are borne by these parts, which are readily renewable whenworn. By the use of piece 17 of different thickness the length of strokeof the plunger can be conveniently regulated. The descent of the plunger6 at the moment the impression-blow is given is suddenly stopped owingto the die coming into contact with the paper resting upon the devicewhich resists the impression-blow, whereupon the plunger immediatelyrebounds upward, its screw, which is made of great or coarse pitch, soas to enable this rebound to occur, causing it to turn from the positionshown in Fig. 6 to approximately that shown in Fig. 7. As some timeelapses before the cam 11 again comes into position to engage with theroller 7, the plunger would be liable to descend and give a second blowunless means were provided to prevent premature descent of the plunger.As the extent to which the plunger rebounds varies, it is necessary thatthe device shall be such as to hold it on the completion of the reboundnotwithstanding Variation within comparatively Wide limits of the extentof the rebound. Figs. 14:, 15, 1G, and 17 are detail views illustratingan arrangement for this purpose. Fixed to opposite portions of thefly-wheel 1.: are a couple of racks 20,having toothed under sides formedas parts of screw-paths of the same pitch as the screw f, so that theyare always in position to engage correctly with pawls 21, fixed tospindles 22, journaled at opposite sides of the cylinder 1). Each pawlis loaded by a coiled spring 23, one end of which is fixed to itsspindle and the other end of which is held between pins 2-1:, so thatthe spring tends to retain the pawl with its nose upward. (See Fig. 17.)As the plunger rebounds the rackteeth depress the pawls 21 against theaction of their springs 23 and slip over them until the reboundceases,whereupon the rack-teeth are engaged by them and the plunger thusprevented from delivering a second blow. \Vith this'arrangementtheplunger cannot'descend prematurely to an extent greater than correspondsto one tooth of the racks 20, no matter whether the rebound is great orlittle. lVhile the raising of the plunger is being completed, aspreviously described, the racks 20 again slip over the pawls 21 until atthe moment the plunger is locked in its uppermost position by thelocking-roller 8 entering the recess 13 the racks clear or move beyondthe pawls, which then assume a vertical attitude under the influence ofthe springs 23. When the plunger descends, the racks move in the reversedirection and their ends come into contact with and push the pawls overbackward, (or to the left,) so that the racks 20 are able to slip overthem. Before the blow is struck the other ends of the racks pass the.

pawls, thus allowing them to again assume a vertical attitude, so thatduring the rebound the racks again depress them and at the end of therebound are again engaged by them and a second blow prevented, aspreviously described.

Each pawl can be turned into a position clear of the rack-teeth byreleasing the end of the spring 23 from the pins 24: and insert ing itbetween pins 25. lVhen the pawls are thus held in their inoperativeattitude, the attendant can while the press is not running form or throwup a counter quickly by op'er ating by hand the fly-wheel, which is thenfree to descend.

The plunger in its descent forces the die block 0 down against theresistance of springs 26, which are connected to the die-block and tothe die-arm, in which it moves and which lift the die 72, clear of thepaper immediately the plunger rebounds and before the said diearm isagain started.

The quick free blow which is struck when apparatus such as hereinbeforedescribed is employed insures the die cl completing its operative strokeand yielding a good impression notwithstanding give or variation of thecounter or equivalent part, arising from constant use, or variations inthickness of paper or other material to be printed or impressed. Anotheradvantage of the quick free rebound blow is that when the machine isused for printing the ink is freely delivered upon the paper or othermaterial, while leaving the edges of the engraving or other device thatis printed sharp and clear, whereas with a dwell blow, especially wheresoft paper or material is printed upon, the ink is liable to spit orrun. Furthermore, the quick rebound blow when using soft paper ormaterial also has the effect of calendering the surface simultaneouslywith the printing of the impression.

That I claim is= 1. In a press of the kind referred to, impres sionmechanism com prising a weighted screwplunger, a fixed nut in which saidplunger works, a continuously-rotating part mounted on said plunger,means whereby said plunger and rotating part are intermittently coupled,means whereby said plunger is temporarily locked in its raised positionand whereby it is subsequently released, and springs which arecompressed by the upward movement of the plunger and subsequently reactthereon so as to cause its rapid descent when released, as set forth.

2. In a press of the kind referred to, llllPlBS- sion mechanismcomprising a weighted screwplunger, a fixed nut in which said plungerworks, means whereby said plunger is successiveiy raised, locked, andreleased, a rack engaging with a pinion formed upon said plunger, and aspring arranged in the path of said 'rack and adapted to be compressedthereby during the upward movement of the plunger, as set forth.

3. In apress of the kind referred to, impression mechanism comprising aweighted screwplnnger, a fixed nut in which said plunger Works, a pinionsecured to said plunger, a rack engaging said pinion, an abutment, aspring arranged between said rack and abutment so as to be compressed asthe rack is moved by the rise of the plunger, a connector secured tosaid plunger, a continuously-rotating part loosely mounted on saidplunger and adapted to intermittently engage said connector, a fixed camadapted to cause the disengagement at the required time of saidconnector and part, a locking device adapted to engage said connectorafter its disengagement from said rotating part and aconnector-releasing cam carried by said continuously-rotating part, asset forth.

4. In impression mechanism, the combination of a weighted screw-plunger,a link pivotally connected to said plunger, a lockingroller carried bysaid link, a guide formed with a recess adapted to receive and hold saidroller, a continuously-rotating part, means for engaging said part tosaid link, means for disengaging said part and link and for causing saidroller to roll into said recess, and means for-causing said roller toroll out of said recess, all at the required times, as set forth.

5. In impression mechanism, the combination of a weighted screw-plunger,a link pivotally connected to said plunger, a lockingroller carried bysaid link, a guide formed with a recess adapted to receive and hold saidroller, and the entry to which is curved, the curve being struck fromthe center of the pivot of said link, a continuously-rotating part,means for engaging said part to said link, means for disengaging saidpart and link and for causing said roller to roll into said recess, andmeans for causing said roller to roll out of said recess all at therequired times, as set forth.

6. In impression mechanism, the combination of a weighted screw-plunger,a link pivotally connected to said plunger, a lockingroller carried bysaid link, a guide formed with a recess adapted to receive and hold saidroller, a continuously-rotating part, a dragroller carried by said link,a cam-arm carried by said part and having its forward face so formed asto make contact with the dragroller at the point at which a line,passing through the axesof said drag-roller and of the pivot of thelink, cuts the periphery of the drag-roller, means for disengaging saidcam-arm and drag-roller and for causing the locking-roller to roll intoand out of said lock ing-recess at the required times, as set forth.

7. In impression mechanism, the combination of a weighted screw-plunger,a link pivotally connected to said plunger, a lockingroller carried bysaid link, a guide formed with a recess adapted to receive and hold saidroller, and the entry 'to which is curved, the

curve being struck from the center of the.

pivot of said link, a continuously-rotating part, a drag-roller carriedby said link, a camarm carried by said part and having its forward faceso formed as to make contact with the drag-roller at the point at whicha line, passing through the axes of said drag-roller and of the pivot ofthe link, cuts the periphery of the drag-roller, means for disengagingsaid cam-arm and drag-roller and for causing the locking-roller to rollinto and out of said locking-recess at the required times, as set forth.

8. In impression mechanism, the combination of a weighted screw-plunger,a continuously-rotating part mounted thereon, a camarm and atripping-cam carried by said part, a link pivotally connected to saidplunger, a drag-roller carried by said link and adapted to be engaged bysaid cam-arm, a lockingroller carried by said link, a guide formed witha recess adapted to receive and hold said lockin g-roller, means fordisengaging said drag-roller from said cam-arm and means for causingsaid locking-roller to roll into and to roll out of said recess at therequired times, as set forth.

9. In impression mechanism, the combination of a weighted screw-plunger,a continuously-rotating part mounted thereon, a camarm and atripping-cam carried by said part, a link pivotally connected to saidplunger, a drag-roller carried by said link and adapted to be engaged bysaid cam-arm, a lockingroller carried by said link, a guide formed witha recess adapted to receive and hold said locking-roller, a cam-rollercarried by said link and adapted to be operated by said tripping-cam atthe required time and a camplate so arranged that said cam-roller willbe brought into contact therewith and the locking-roller caused tobecome engaged with the guide at the required time, as set forth.

10. In impression mechanism, the combination of the fixed cylinder orcasing, a fixed nut in line therewith, a screw-plunger work ing in saidnut and extending through said cylinder or casing .a continuously-drivenspurwheel free to rotate on said plunger, a link pivotally connected tosaid plunger, a dragroller,a locking-roller and a cam-roller mounted onsaid link, a guide with'recess and a cam-plate both carried by saidcylinder or casing and a cam-arm and tripping device both carried bysaid spur-Wheel as set forth.

11. In impression mechanism, the combination of a fixed cylinder orcasing, the fixingnnt in line therewith, a screw-plunger working in saidnut and extending through said cylinder or casing,a continuously-drivenspurwheel free to rotate on said plunger, a link pivotally connected tosaid plunger, a dragroller,a locking-roller and a cam-roller mounted onsaid link, a guide with recess and a cam-plate both carried by saidcylinder or casing and a camarm and tripping device both carried by saidspur-wheel, a pinion fixed to said plunger, a pair of sliding racksextending toward abutments, and springs arranged between said racks andabutments, the parts being adapted to operate so as to cause theraising, locking, releasing and descent of the plunger as set forth.

12. In impression mechanism, the combination of a screw-plunger, a linkpivotally connected to said plunger, alocking-roller carried by saidlink, a recess adapted to receive said roller, a continuously-rotatingpart,

means for engaging and for disengaging said part and link, as set forth.

13. In impression mechanism, the combination of a screw-plunger, a linkpivotally connected to said plunger, a locking-roller and a drag-rollercarried by said link, a recess adapted to receive said locking-roller, acontinuously-rotating part, an arm connected to said part and having aforward face adapted to engage said drag-roller and an outer faceadapted to bear against said drag-roller as set forth.

ll. In impression mechanism, the combination of a screw-plunger, a linkpivotally connected to said plunger, a locking-roller and a drag-rollercarried by said link, a recess adapted to receive said locking-roller, acontinuously-rotating part, an arm connected to said part and having aforward face adapted to engage said drag-roller and an outer faceadapted to bear against said drag-roller, and means for disengaging saiddrag-roller from said arm, as set forth.

15. In impression mechanism, the combination with a screw-plunger of afiy-wheel secured thereto, a continuously-rotating part loosely mountedon said plunger, means for connecting said plunger and part and meansfor preventing longitudinal movement of said rotating part along saidplunger, as set forth.

16. In impression mechanism, the combination with a screw-plunger of afiy-wheel secured thereto, a continuously-rotating part loosely mountedon said plunger, means for connecting said plunger and part, a sleevefitting said plunger and extending between said fly-wheel and part, asset forth.

17. In impression mechanism the combina tion with a screw-plunger of afly-wheel secured thereto, a continuously-rotating part loosely mountedon said plunger, means for connecting said plunger and part, a sleevefitting said plunger and extending between said fiy-wheel and part, anda bearingin which said sleeve is journaled, as set forth.

18. In impression mechanism of a press of the kind referred to, thecombination of a.

Weighted screw-plunger, a fixed nut in which said plunger works, acontinuously-rotating part mounted on said plunger, means whereby saidplunger and rotating part are intermittently coupled, means whereby saidplunger is temporarily locked in its raised position and whereby it issubsequently released, and means whereby it is prevented from descendingon the completion of its rebound until it has again been raised to thetop of its stroke, which means are independent of saidcontinueusly-rotating part, as set forth.

19. In impression mechanism the combination of a screw-plunger, plungerraising, lock ing and releasing means, a cylinder or casing surroundingsaid means, and a cover to said cylinder or casing, said cover beingformed with a central aperture or hearing through which said plungerextends, as set forth.

20. In impression mechanism, the combination of a screw-plunger, plungerraising, looking and releasing means, a pinion secured to said plunger,a pair of sliding racks gearing therewith, rack-guides, fixed boxes intowhich said racks extend, cap-nuts closing the ends of said boxes, andcoiled springs located in said boxes, as set forth.

21. In impression mechanism, the combination of a screw-plunger, plungerraising, looking and releasing means, a pinion secured to said plunger,a pair of sliding racks gearing therewith, rack-guides, fixed boxes intowhich said racks extend, cap-nuts closing the ends of said boxes,andcoiled springs located in said boxes, said springs being of suchlength that they will not exert pressure on the racks and plunger whenthe latter is at the end of its impression-stroke as set forth.

22. In impression mechanism the combination of a screw-plunger, plungerraising, locking and releasing means, a pinion secured to said plunger,a pair of sliding racks gearing therewith, rackguides, fixed boxes intowhich said racks extend, cap-nuts closing the ends of said boxes, andcoiled springs located in said boxes, and spring-adj usting screws asset forth.

23. In impression mechanism the combination of a screw=plunger, plungerraising, lock ing and releasing means, a pinion secured to said plunger,a pair of sliding racks gearing therewith, rack-guides, fixed boxes intowhich said racks extend, cap-nuts closing the ends of said boxes, andcoiled springs located in said boxes, screw-threaded apertures throughsaid cap-nuts, screw-spindles with heads and hand-wheels and workingthrough said apertures and lock-nuts as set forth;

24. In impression mechanism the combina tion of a screw-plunger, plungerraising, looking and releasing means, and a device which is notpositively driven but is adapted to auto matically engage at the end ofthe rebound with a part attached to the plunger and to hold it until ithas again been raised and looked as ing and releasing means, a rackcarried by said plunger, and a pawl pivoted in fixed bearings, so as toengage with said rack at the required time as set forth.

27. In impression mechanism the combination of a screw-plunger, plungerraising, looking and releasing means, a rack carried by said plunger andhaving its toothed surface formed as part of a screw-path and a pawlpivoted in fixed bearings so as to engage with said rack at the requiredtime, as set forth.

28. In'impression mechanism, the combination of a screw-plunger, plungerraising, locking and releasing means, a rack carried by said plunger andhaving its toothed surface formed as part of a screw-path and a pawlpivoted in fixed bearings so as to engage with said rack at the requiredtime, the length of the rack being such that it will clear or movebeyond the said pawl at the ends of both the impression and returnstrokes of the plunger, as set forth.

29. In impression mechanism the combination of a screw-plunger, plungerraising,1ocking and releasing means, a rack oarriedby said plunger andhaving its toothed surface formed as part of a screw-path and a pawlpivoted in fixed bearings so as to engage with said rack atthe requiredtime, and so loaded as to point lengthwise of the plunger as set forth.

30. In impression mechanism, the combination of a screw-plunger, plungerraising, locking and releasing means, a fly-wheel secured to the upperpart of said plunger, racks secured thereto and having toothed undersides formed as parts of screw-paths,pawls fixed to spindles journaledin fixed bearings so as to be capable of being turned in eitherdirection, springs connected to said spindles and tending to retain saidpawls pointing upwardly, the length of the said racks being such thatthey will clear or move beyond their respective pawls at the ends ofboth the im- 31. Inimpressionmechanism,thecombina- I tion of ascrew-plunger, plunger raising, looking and releasing means, a fiy-wheelsecured to the upper part of said plunger, racks secured thereto andhaving toothed under sides formed as parts of screw-paths,pawls fixed tospindles journaled in fixed bearings so as to be capable of being turnedin either direction, helical springs one of which is attached by itsinner convolution to each pawl-spindle, means for detachably securingthe outer end of each spring in either of two positions, in one of whichthe pawl will be operative in the other inoperative as set forth.

32. In impression mechanism the combination of a screw-plunger, plungerraising, locking and releasing means, a fly-wheel secured to the upperpart of said plunger, racks secured thereto and having toothed undersides formed as parts of screw-paths, pawls fixed to spindles journaledin fixed bearings so as to be capable of being turned in eitherdirection, springs connected to said spindles and tending to retain saidpawls pointing upwardly, thelength of the said racks being such thatthey will clear or move beyond their respective pawls at the ends ofboth the impression and return strokes of the die-plunger, permittingsaid pawls to assume a vertical attitude at such times and pushing saidpawls into an operative position at the coinmencement of the ascent ofthe plunger and into a reverse or inoperative position at thecommencement of its descent to give the impression, as set forth.

Signed at 22 Bride Lane, London, England, this 12th day of January,1900.

JOSE PH YARDLEY JOHNSTON.

Vitnesses:

WILLIAM B. CHILD, ARTHUR WoosNAM.

